Igniters are an integral component of many devices, including automobile passenger restraint systems (airbags), seat belt tensioning devices, blasting charges for mining or construction, and the like. Unfortunately, many of the igniters currently available on the market have significant drawbacks with respect to ease and cost of manufacturing, as well as other issues. For example, many of the currently available igniters require the use of a bridge wire which must be soldered into place—a time-consuming, labor-intensive, and ultimately costly manufacturing step. As such, it is difficult for such igniters utilizing bridge wires to be efficiently and/or inexpensively mass-produced. The soldered-on bridge wires can be fairly easily dislodged and, as a result, the reliability of igniter performance is often unacceptably low. Furthermore, many of the currently available igniters are stand-alone devices which can be difficult to integrate with other electronic components.
In addition, many of the currently available igniters require the use of explosive or “energetic” materials. Handling and use of such materials can be dangerous and the manufacture of devices utilizing such materials is often governed by various state or federal regulations. Furthermore, igniters incorporating explosive or energetic materials can generate sparks and can require the presence of a heat shield and/or other protective measures to prevent multiple or uncontrolled ignitions that could lead to non-uniform heating of a supporting substrate.
Another drawback of previous igniters is that they typically require a high energy input. Prior art igniters had electrodes which were spaced relatively far apart, requiring more material and a higher actuation energy.